Drive for drying cylinder assemblies

ABSTRACT

THE INVENTION PROVIDES A DRIVE FOR DRYING CYLINDER ASSEMBLIES UPON WHICH THERE CAN BE DRIED A BAND MATERIAL, PARTICULARLY TEXTILE WEBS OR BANDS OF FILAMENTS, THAT CHANGES ITS LENGTH AS IT DRIES. THIS DRIVE COMPRISES A SINGLE MOTOR FOR DRIVING THE SEVERAL CYLINDERS OF A DRYING CYLINDER   ASSEMBLY AT DIFFERENT SPEEDS BY DRIVING EACH PAIR OF CONSECUTIVE PAIRS OF SAID CYLINDERS THROUGH AT LEAST ONE DIFFERENTIAL GEAR.

Feb. 9, 1971 w. KRUCKELS ETAL 3,561,134

- DRIVE FOR DRYING CYLINDER ASSEMBLIES Filed om". 14, 1968 sSheets-Sheet 1 INVNTMf: uALreR Knacks ERwM Gums! m aw M M Feb. 9, 1971w, KRUCKELS ETAL 3,561,134

DRIVE FOR DRYING CYLINDER ASSEMBLIES 3 Sheets-Sheet 2 v Filed Oct. 14,1968 1 M Q aw U W FL N W; K M r m E H 8 mw m TS 3 w Ill? v a m n H kw HXi) @W L m .Q. Q .llIvLiiHU J M QMJMVJ R \flW fi EWFQM, a 1 N1 m F E wwQ .T Q L mw v mm, Q Q v Q em aw \& Q 7 W W V. J G Q. J o k Q Q g 0 Feb.9, 1971 I w, U L ETAL 3,561,134

DRIVE FOR DRYING CYLINDER ASSEMBLIES Filed Oct. 14, 1968 v 3Sheets-Sheet 3 7 H I w a WLX Q l/Eryr WRLHEF Ha ERIcH Gdflmsm 73 US. Cl.34-121 2 Claims ABSTRACT OF THE DISCLOSURE The invention provides adrive for drying cylinder assemblies upon which there can be dried aband material, particularly textile webs or bands of filaments, thatchanges its length as it dries. This drive comprises a single motor fordriving the several cylinders of a drying cylinder assembly at differentspeeds by driving each pair of consecutive pairs of said cylindersthrough at least one differential gear.

BACKGROUND OF THE INVENTION When a material that stretches or shrinks asit dries is conveyed over an assembly of consecutive drying cylinders,the length of the travelling material changes according to the rate atwhich it stretches or shrinks. It follows that consecutive dryingcylinders in the direction of travel of the material must be driven atdifferent speeds if the generation of undesirable tension in thematerial is to be avoided.

Drive means for the drying cylinders of a sizing or like textiletreating machine have already become known in the art, in which theseveral cylinders are driven by a driving element in the form of anendless belt or chain which is led around the cylinder journals or thepulleys firmly mounted thereon, and in which the non-positive drivingengagement between the driving element and the cylinders can be partlyor wholly released according to the acceleration and/ or the tension ofthe travelling drying material. During acceleration or retardation theseveral cylinders therefore continue to be driven, but the size of thepulleys which are nonpositively engaged by the driving element must becarefully chosen so as to ensure that the associated cylinder will infact assume the peripheral speed which makes the correct allowance forthe shrinkage of the material. This is difficult to effect and a specialadjustment must be made for each material that is to be dried.

SUMMARY OF THE INVENTION It is the object of the present invention toprovide a drive of the above specified kind in which all the cylindersare positively driven and their peripheral speeds can neverthelessprecisely adjust themselves to the local speed of the travellingmaterial.

To attain this object, the present invention provides a drive for dryingcylinder assemblies upon which there can be dried a band material,particularly textile webs or hands of filaments, that changes its lengthas it dries, which comprises a single motor for driving the severalcylinders of a drying cylinder assembly at different speeds by drivingeach pair of consecutive pairs of cylinders through at least onedifferential gear.

At least one of the cylinders, assuming an odd number of cylinders inthe assembly, may preferably be driven by the common motor through anadjustably variable gearing at a selectable constant speed, whereas thedifferential gears for driving the remaining cylinder pairs are drivenUnited States Patent by the common motor through at least one furtheradjustably variable gearing.

Moreover, the differential gears driving two consecutive pairs of thecylinders may themselves be differentially driven by the common motorthrough a further differential gear which in turn is driven by thecommon motor through the further adjustably variable gearing.

The proposed drive for drying cylinder assemblies permlts each cylinderto adjust its peripheral speed to the speed of the material running overthis cylinder, notwithstanding that all the cylinders are positivelydriven. The generation of undesirable tension in the drying material canthus be substantially avoided.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention willnow be described by way of example and with reference to theaccompanying schematic drawings in which:

FIG. 1 is a top plan view of an assembly of drying cylinders and oftheir associated drive means, components and details not required for anunderstanding of the invention having been omitted;

FIG. 2 is a side elevational view of the assembly according to FIG. 1,and

FIG. 3 is a view of the assembly, similar to FIG. 2, below a graph in anx, y-coordinate system, showing the peripheral speeds of the severalcylinders.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to these drawings acontinuous tape or band of material 10 that is to be treated,particularly dried, is indicated by a thick line. This material 10 mayfor instance be a freshly sized tape for warping which is to be dried ona drying cylinder assembly composed of drying cylinders 11 to 15. InFIG. 2 the material runs through the machine from lift to right. It isfirst gripped between a pair of driven fed rollers 16 which extract itfrom a dressing trough (not shown) and feed it to the drying cylinders.The reference numeral 17 designates a deflecting roller preceding thecylinder assembly, the roller being mounted on a tilting arm 21 loadedby a tension spring 20. This deflecting roller 17 is incidentally alsoused for measuring the tension of the material 10 before it enters thecylinder assembly.

The drying cylinders 11 to 15 are each partly enveloped by the material10 that is to be treated. The material then runs over a set of drivingrollers 18 and is finally wound on a beam 19'.

A common motor 22 drives, by means of a belt 23, a shaft 24 of which oneend drives the set of driving rollers 18. At the same time, throughtransmission means 47, the shaft 24 drives an adjustably variable.gearing 48 of which the output shaft 49 is coupled to the beam 19. Theadjustably variable gearing 48 is preferably so controlled that thetension in the portion of the material 10 which has been wound up iskept substantially constant. The gearing 48 may be controlled in anyconventional manner known in the art.

Furthermore, through a pair of bevel gears 25 the other end of the shaft24 drives an adjustably variable gearing 26 which permits the speed ofrotation of the output shaft of bevel gears 25 to be varied, thusrendering it possible to drive the drying cylinder 15, through a furtherpair of bevel gears 27 and a shaft 28, at a selectable speed.

The adjustably variable gearing 26 simultaneously drives a furtheradjustably variable gearing 29 which in turn drives a pair of bevelgears 30. This pair of bevel gears 30 drives an input shaft 31 of adifferential gear 32 of which the two outputs, through transmissions 33and 52, drive the input shafts 34 and 35 of two further differentialgears 50 and 51. The outputs of these latter differential gears 50 and51, through transmission means 36, 37, 40, 41, drive shafts 38, 39, 42and 43 of the drying cylinders 11 to 14. Since all the drying cylinders11 to 14 are thus driven through differential gears, the individualcylinders can adjust their peripheral speeds to the speed of thematerial 10, notwithstanding the fact that all the drying cylinders aredriven. This adjustment of the peripheral speeds of the drying cylinders11 to 14 is entirely automatic and no special adjustment or control ofthe transmission means is required.

Besides the pair of bevel gears 30, the further adjustably variablegearing 29 also drives another adjustably variable gearing 44 which inturn drives another pair of bevel gears 45 and a shaft 46 for rotatingthe pair of feed rollers 16.

It is not essential that the arrangement of the differential gearsshould be as shown in the drawings. As an alternative, each pair ofdrying cylinders could be driven by one differential gear and thisdifferential gear could be directly driven by the common motor 22,preferably through an adjustably variable gearing. However, thedescribed arrangement has proved to be particularly satisfactory.

It will also be understood that it is not of the essence that the finaldrying cylinder 15 over which the material 10 passes last should bedirectly or indirectly driven through an adjustably variable gearing bythe common motor 22. In principle it would be quite feasible to driveany one of the drying cylinders in this way and to drive each of theremaining pairs of drying cylinders through differential gears.

Moreover, instead of the illustrated bevel-type differentials,differentials of any other form of construction could naturally be used.

A substantial advantage afforded by the invention is that each dryingcylinder 11, 12, 13, 14 and possibly 15 can adapt its peripheral speedto the linear speed of the travelling material 10, even if this shouldshrink or stretch during the drying process. The tension in the dryingmaterial between consecutive cylinders remains quite small, despite thefact that each cylinder is driven. Undesirable tension in the dryingmaterial, which may readily arise when the material itself drives thecylinders, is thus avoided.

The feed through the machine may be controlled by the feed roller pair16 instead of by the pair of driving rollers 18, in which case theformer would be directly connected to the driving motor 22.

Control when the tension in the material 10 varies can be effected asfollows, assuming that the drying cylinder 15 is driven to revolve at aconstant speed:

Let it be assumed that the material 10 travelling from the pair of feedrollers 16 to the final drying cylinder 15 stretches significantlyduring the drying process so that the peripheral speeds v v v12, v v 1progressively increase. This is schematically shown in the graph in FIG.3. The position of the x-axis need not necessarily represent a speedv=0. The curve V; will then roughly reflect the elongation of thematerial which in the illustrated example increases roughly linearlyfrom the feed roller pair 16 to the final cylinder 15. Should the rateof elongation of the material become less or in some other way cease tobe in accordance with the abovementioned curve V then this will lead toa change in position of the deflecting roller 17 which also serves tomeasure the tension of the material, and which will be hereinafterreferred to as the measuring deflecting roller 17. When the tension inthe material 10 rises this measuring deflecting roller 17 transmitscontrolling signals proportional to its deflection to the two variablegearings 44 and 29. Let it be assumed for instance that the speed v ofthe pair of feed rollers 16 must be raised by Av to adequately adjustthe speed of entry and hence the quantity of the web of the material 10fed into the machine by the feed rollers 16 to the stretching of thematerial 10 between the feed rollers 16 and the last drying cylinder 15.Since the measuring deflecting roller 17 responds both to excessivelyhigh and excessively slack tension, it is well adapted to control thepair of feed rollers 16 to the desired speed of draw-in. Since thechange in length between the pair of feed rollers 16 and the finaldrying cylinder 15 corresponds to a change in speeds, reflected by thecurve V which is substantially proportional to the previous speed curveV the two curves V and V in the illustrated example being taken aslinear-the entire drive of the assembly of drying cylinders 11 to 14must experience an average speed increase Av which can be taken from thediagram at the midway point between the speeds v and v which correspondto the speeds of the drying cylinders 11 to 14. This increase in speedAv must also be taken into account by appropriately adjusting thegearing 29 when the gearing 44 is adjusted as above described. If theelongation or shrinkage proceeds linearly, as is assumed in the diagram,then the signal for adjusting the gearing 29 should make an adjustmentequal to half that of the gearing 44. If the pattern of elongation orshrinkage is different, appropriate adjustments are possible. Theincrease in speed is transmitted through the pair of bevel gears 30, theshaft 31, the differential gear 32 and the following differentialtransmissions 33 to 43 and to 52 to the drying cylinders 11 to 14.

In chain lines the graph in FIG. 3 also shows another speed curve Vwhich corresponds to a higher peripheral speed of the feed rollers 16than that of the final drying cylinder 15. This type of speed curvearises when the drying material 10 undergoes shrinkage in length whilsttravelling from the feed rollers 16. to the final drying cylinder 15. Ina system of controlling the two gearings 44 and 29 by reference tosignals generated by the measuring deflecting roller 17, this controlsignal may, if desired, first be applied to the gearing 29 whichcontrols the average difference in speed Av of the drying cylinders 11to 14, and the speed difference Av required at the feed rollers 16 maybe derived therefrom, or, alternatively, the difference in speed Av ofthe pair of feed rollers may be adjusted first and the difference inspeed Av required for driving the four drying cylinders 11 to 14 may beadjusted by reference thereto. It is not absolutely necessary that thelast drying cylinder 15, as seen in the direction of travel, should bethe cylinder rotating at a constant peripheral speed v for an adjustmentof the other speed differentials in the aforementioned system 11 to 16.In some cases it may be desirable in certain drying operations to drivethe pair of driving rollers 18 at a constant reference speed and theabove-described system of control may then also include the final dryingcylinder 15. It may then be an advantage to provide for driving the pairof driving rollers 18 and the drying cylinder 15 at different speeds, apossibility which is available, for instance, because of the presence ofthe gearing at 26, and control signals for matching the peripheralspeeds of the driving rollers 18 and that of the final drying cylinder15 may if desired be derived from a further measuring and deflectingroller 17a.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description and all changeswhich come within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

What is claimed is:

1. In mechanism for driving drying cylinder assemblies upon which a bandmaterial that changes its length as it dries, such as textile webs,bands and filaments, can be dried, the improvement comprising, incombination, a single motor for driving the several consecutivecylinders of said assembly at different speeds; an adjustable speedtransmission connecting said motor to at least one cylinder for drivingsaid one cylinder at an adjustable constant speed; at least one furtheradjustable speed transmission driven by said motor; two differentialgears each having outputs connected to the cylinders of a respectivepair of drying cylinders, the two pairs of drying cylinders beingconsecutive; and a further difierential gear having its input connectedto the output of said further adjustable speed transmission, and havingtwo outputs, each con 10 entry and delivery ends of said drying cylinderassembly of which at least one set is connected to said motor throughanother adjustably variable gearing.

References Cited UNITED STATES PATENTS 1,594,394 8/1926 Weston 226-402,531,644 11/1950 Rayburn 22611l 3,119,537 1/1964 Smits 226188X RICHARDA. SCHAOHER, Primary Examiner US. Cl. X.R. 226-111, 188

